To fuck someone over. To act deceitful or two faced. To cause someone to believe something that is not true. To stab someone in the back.
What do you mean we were bitching about pay! Damn, I just got kunselnated.
I thought Sam said that we were all getting pay raises. Damn, I just got kunselnated.
You better watch your back. If you don't you might get kunselnated.